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Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biological sex plays a prominent role in the prevalence and severity of a number of important stress-related gastrointestinal and immune-related diseases including IBS and allergy/anaphylaxis. Despite the establishment of sex differences in these diseases, the underlying mechanisms contributing to sex differences remain poorly understood. The objective of this study was to define the role of biological sex on mast cells (MCs), an innate immune cell central to the pathophysiology of many GI and allergic disorders.

Methods: Twelve-week-old C57BL/6 male and female mice were exposed to immunological stress (2 h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1 h of restraint stress (RS)) and temperature, clinical scores, serum histamine, and intestinal permeability (for RS) were measured. Primary bone marrow-derived MCs (BMMCs) were harvested from male and female mice and analyzed for MC degranulation, signaling pathways, mediator content, and RNA transcriptome analysis.

Results: Sexually dimorphic responses were observed in both models of PSA and RS and in primary MCs. Compared with male mice, female mice exhibited increased clinical scores, hypothermia, and serum histamine levels in response to PSA and had greater intestinal permeability and serum histamine responses to RS. Primary BMMCs from female mice exhibited increased release of β-hexosaminidase, histamine, tryptase, and TNF-α upon stimulation with IgE/DNP and A23187. Increased mediator release in female BMMCs was not associated with increased upstream phospho-tyrosine signaling pathways or downstream Ca2+ mobilization. Instead, increased mediator release in female MCs was associated with markedly increased capacity for synthesis and storage of MC granule-associated immune mediators as determined by MC mediator content and RNA transcriptome analysis.

Conclusions: These results provide a new understanding of sexual dimorphic responses in MCs and have direct implications for stress-related diseases associated with a female predominance and MC hyperactivity including irritable bowel syndrome, allergy, and anaphylaxis.

Electronic supplementary material: The online version of this article (doi:10.1186/s13293-016-0113-7) contains supplementary material, which is available to authorized users.

No MeSH data available.


A23187-induced degranulation and Ca2+ mobilization in female and male murine BMMCs. BMMCs were stimulated for 1 h with the Ca2+ ionophore, A23187 (1 μM). a BMMCs from females showed a 50.6% increase in β-hexosaminidase release and male BMMCs showed a 39.9% increase, a difference that was significant (P < 0.001; n = 6). b Female BMMCs released 406.1 ng/106 cells of histamine into supernatant and male BMMCs released 159.3 ng/106 cells of histamine (P < 0.001; n = 5). c Tryptic activity (ΔOD405/min/106 cells) from female BMMCs increased to 7.6 after degranulation, and tryptic activity from male BMMCs was 3.2 after degranulation (P < 0.001; n = 4). d Female BMMCs released 165.7 pg of TNF-α into supernatant and male BMMCs released 103.4 pg (P < 0.01; n = 4). All mediator release was normalized to unstimulated cells of respective sex. e Female and male BMMCs exhibited similar Ca2+ influx as measured by e Ca2+ tracings and quantified as the f change in peak fluorescence after stimulation with A23187 (1 μM). Values represent mean ± SE. **P < 0.01, ***P < 0.001 vs. males
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Fig6: A23187-induced degranulation and Ca2+ mobilization in female and male murine BMMCs. BMMCs were stimulated for 1 h with the Ca2+ ionophore, A23187 (1 μM). a BMMCs from females showed a 50.6% increase in β-hexosaminidase release and male BMMCs showed a 39.9% increase, a difference that was significant (P < 0.001; n = 6). b Female BMMCs released 406.1 ng/106 cells of histamine into supernatant and male BMMCs released 159.3 ng/106 cells of histamine (P < 0.001; n = 5). c Tryptic activity (ΔOD405/min/106 cells) from female BMMCs increased to 7.6 after degranulation, and tryptic activity from male BMMCs was 3.2 after degranulation (P < 0.001; n = 4). d Female BMMCs released 165.7 pg of TNF-α into supernatant and male BMMCs released 103.4 pg (P < 0.01; n = 4). All mediator release was normalized to unstimulated cells of respective sex. e Female and male BMMCs exhibited similar Ca2+ influx as measured by e Ca2+ tracings and quantified as the f change in peak fluorescence after stimulation with A23187 (1 μM). Values represent mean ± SE. **P < 0.01, ***P < 0.001 vs. males

Mentions: As an additional functional experiment to confirm that the increased granule mediator content in female mice was contributing to heightened mediator release during degranulation, we measured MC degranulation and Ca2+ mobilization in BMMCs in response to the Ca2+ ionophore A23187, which acts downstream of receptor activation to trigger Ca2+ influx and MC degranulation. Similar to IgE/DNP-stimulation responses, female BMMCs released greater amounts of β-hexosaminidase, histamine, tryptase, and TNF-α in response to A23187 than male BMMCs. Also in line with IgE/DNP stimulation, there were no differences in Ca2+ mobilization responses between male and female BMMCs (Fig. 6a–f).Fig. 6


Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress
A23187-induced degranulation and Ca2+ mobilization in female and male murine BMMCs. BMMCs were stimulated for 1 h with the Ca2+ ionophore, A23187 (1 μM). a BMMCs from females showed a 50.6% increase in β-hexosaminidase release and male BMMCs showed a 39.9% increase, a difference that was significant (P < 0.001; n = 6). b Female BMMCs released 406.1 ng/106 cells of histamine into supernatant and male BMMCs released 159.3 ng/106 cells of histamine (P < 0.001; n = 5). c Tryptic activity (ΔOD405/min/106 cells) from female BMMCs increased to 7.6 after degranulation, and tryptic activity from male BMMCs was 3.2 after degranulation (P < 0.001; n = 4). d Female BMMCs released 165.7 pg of TNF-α into supernatant and male BMMCs released 103.4 pg (P < 0.01; n = 4). All mediator release was normalized to unstimulated cells of respective sex. e Female and male BMMCs exhibited similar Ca2+ influx as measured by e Ca2+ tracings and quantified as the f change in peak fluorescence after stimulation with A23187 (1 μM). Values represent mean ± SE. **P < 0.01, ***P < 0.001 vs. males
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Fig6: A23187-induced degranulation and Ca2+ mobilization in female and male murine BMMCs. BMMCs were stimulated for 1 h with the Ca2+ ionophore, A23187 (1 μM). a BMMCs from females showed a 50.6% increase in β-hexosaminidase release and male BMMCs showed a 39.9% increase, a difference that was significant (P < 0.001; n = 6). b Female BMMCs released 406.1 ng/106 cells of histamine into supernatant and male BMMCs released 159.3 ng/106 cells of histamine (P < 0.001; n = 5). c Tryptic activity (ΔOD405/min/106 cells) from female BMMCs increased to 7.6 after degranulation, and tryptic activity from male BMMCs was 3.2 after degranulation (P < 0.001; n = 4). d Female BMMCs released 165.7 pg of TNF-α into supernatant and male BMMCs released 103.4 pg (P < 0.01; n = 4). All mediator release was normalized to unstimulated cells of respective sex. e Female and male BMMCs exhibited similar Ca2+ influx as measured by e Ca2+ tracings and quantified as the f change in peak fluorescence after stimulation with A23187 (1 μM). Values represent mean ± SE. **P < 0.01, ***P < 0.001 vs. males
Mentions: As an additional functional experiment to confirm that the increased granule mediator content in female mice was contributing to heightened mediator release during degranulation, we measured MC degranulation and Ca2+ mobilization in BMMCs in response to the Ca2+ ionophore A23187, which acts downstream of receptor activation to trigger Ca2+ influx and MC degranulation. Similar to IgE/DNP-stimulation responses, female BMMCs released greater amounts of β-hexosaminidase, histamine, tryptase, and TNF-α in response to A23187 than male BMMCs. Also in line with IgE/DNP stimulation, there were no differences in Ca2+ mobilization responses between male and female BMMCs (Fig. 6a–f).Fig. 6

View Article: PubMed Central - PubMed

ABSTRACT

Background: Biological sex plays a prominent role in the prevalence and severity of a number of important stress-related gastrointestinal and immune-related diseases including IBS and allergy/anaphylaxis. Despite the establishment of sex differences in these diseases, the underlying mechanisms contributing to sex differences remain poorly understood. The objective of this study was to define the role of biological sex on mast cells (MCs), an innate immune cell central to the pathophysiology of many GI and allergic disorders.

Methods: Twelve-week-old C57BL/6 male and female mice were exposed to immunological stress (2&nbsp;h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1&nbsp;h of restraint stress (RS)) and&nbsp;temperature, clinical scores, serum histamine, and intestinal permeability (for RS) were measured. Primary bone marrow-derived MCs (BMMCs) were harvested from male and female mice and analyzed for MC degranulation, signaling pathways, mediator content, and RNA transcriptome analysis.

Results: Sexually dimorphic responses were observed in both models of PSA and RS and in primary MCs. Compared with male mice, female mice exhibited increased clinical scores, hypothermia, and serum histamine levels in response to PSA and had greater intestinal permeability and serum histamine responses to RS. Primary BMMCs from female mice exhibited increased release of &beta;-hexosaminidase, histamine, tryptase, and TNF-&alpha; upon stimulation with IgE/DNP and A23187. Increased mediator release in female BMMCs was not associated with increased upstream phospho-tyrosine signaling pathways or downstream Ca2+ mobilization. Instead, increased mediator release in female MCs was associated with markedly increased capacity for synthesis and storage of MC granule-associated immune mediators as determined by MC mediator content and RNA transcriptome analysis.

Conclusions: These results provide a new understanding of sexual dimorphic responses in MCs and have direct implications for stress-related diseases associated with a female predominance and MC hyperactivity including irritable bowel syndrome, allergy, and anaphylaxis.

Electronic supplementary material: The online version of this article (doi:10.1186/s13293-016-0113-7) contains supplementary material, which is available to authorized users.

No MeSH data available.